Torpedo motor mounting structure



Stats 3,145,678 Patented Aug. 25, 1964 3,145,678 TQRPEDG MOTGR MUUN'HNGSTRUCTURE John G. Shmorliun and Elbert H. Lenher, Baltimore, Md,assignors, by mesne assignments, to the United States of America asrepresented by the Secretary of the Navy Filed Nov. 21, 1961, Ser. No.154,681 3 Claims. (tll. 114-20) The present invention relates totorpedoes, and more particularly to a new and improved torpedopropulsion motor mounting structure which provides noise-isolation andfacilitates motor installation and removal.

The invention is directly intended for use in torpedoes ofacoustic-homing type wherein transmission of propulsion motor noiseenergy, in any manner, to the electroacoustic transducer which isgenerally mounted in the nose section, causes serious reduction of themaximum range at which target submarine signals can be detected by theacoustic-homing torpedo. While various other noise-isolation mountingshave been proposed heretofore, they have not been entirely satisfactoryfrom the standpoint that they impose disadvantageous design limitationsupon the propulsion motor and the torpedo section (generally thetailcone section) in which the motor is mounted. Such limitations arosefrom the need, in earlier practice, to provide accessibility to themountings aft of the comparatively large, high-powered propulsion motor,for the motor is short-period-rated and must frequently be removed forinspection and maintenance purposes as necessary after testing orproofing the torpedoes before placing them in warshot readiness.

It is an object of the invention to provide a noise-isolating torpedomotor mounting structure which eliminates any need for motor andtailcone section design compromises to provide for accessibility to aftmounts.

It is another object of the invention to provide a noiseisolatingtorpedo motor mounting structure which effects significant reduction ofthe normally considerable circum ferential clearance between a torpedotailcone section and the propulsion motor which it carries.

Another object is to provide a noise-isolating torpedo motor mountingstructure which facilitates motor installation and removal operations.

A further object of the invention is to provide a noiseisolating torpedomotor mounting structure which yields improved noise-isolation andshock-protection characteristics.

Other objects, features and attendant advantages accomplished andprovided by the present invention will become apparent as the inventionbecomes better understood by reference to the following detaileddescription when considered in connection with the accompanying drawingin which like reference numerals designate like parts throughout thefigures thereof and wherein:

FIG. 1 illustrates generally and schematically an acoustic-homingtorpedo and the general locations therein of the propulsion motor andother torpedo components;

FIG. 2 is an enlarged sectional view of the torpedo tailcone section andthe propulsion motor as mounted therein, taken along the line 2-2 ofFIG. 1;

FIG. 3 is a partial face view of a clamp-ring member forming part of themounting structure, taken in the direction indicated by arrow 3 in FIG.2;

FIG. 4 is an enlarged sectional view of the clamp-ring members, takenalong the line 44 as indicated in FIG. 3; and

FIG. 5 is an enlarged sectional view of a noise-isolation and shockprotection member forming part of the motor mounting structure, taken inthe region indicated by arrow 5 in FIG. 2.

In the exemplary embodiment incorporating principles of the presentinvention, as next described in greater detail,

the frame or casing of the torpedo propulsion motor is provided withend-bells having generally frusto-conical surfaces, and the torpedotailcone section is provided with a pair of forward and aft ring-shapedribs located at the motor end-bell stations. The motor mountingstructure further includes a pair of noise-isolation ring-shaped memberswhich are tapered to seat upon the end-bells of the motor, and aclamp-ring member which is removably secured to the forward rib in amanner to clamp the propulsion motor and its noise-isolation membersbetween the clamp-ring member and the aft rib.

Referring first to FIG. 1 which illustrates the exemplary embodiment ina general manner as to the overall configuration of an acoustic-homingtorpedo l0 employing a propulsion motor 12, the torpedo may of course beentirely conventional, except for the manner in which the motor 12 ismounted in accordance with the present invention to providenoise-isolation and facilitate motor mounting, demounting and remountingoperations. The torpedo is structurally sectionalized as indicated, andpro vided with means (not shown) for releasably joining the severalsections so that they may be disengaged and separated when necessary forinspection, maintenance or other purposes. Mounted at the forward end ofthe acoustichoming torpedo 10 is its electro-acoustic transducer 14. Theassociated electronic apparatus 16, which functions to provide targetdetection and homing control, may be carried by the intermediate section18 as indicated. The tailcone section 20 accommodates the propulsionmotor 12, the drive shaft assembly 22, other driven elements (not shown)including conventional noise-isolation couplings, also actuatormechanism (not shown) for providing torpedo steering in response tocontrol signals delivered by the electronic apparatus 16. For thepurpose of substantially eliminating counter-torque forces, the torpedo10 may include counter-rotating propellers 24, 26 as indi cated, inwhich instance motor 12 is preferably of a conventional type whereinboth the rotor and field structures (not shown) are arranged to rotate,in opposite directions Within the motor casing, todrive the propellers24, 26 through concentric shafts of drive shaft assembly 22. It is alsopreferable, for the purpose of enabling motor 12 (when demounted) to beremoved from the torpedo tailcone section 26 without first requiringremoval of the propellers 24, 26 or other components, to conventionallyinclude a splined or other slipjoint type of coupling (not shown) in themotor drive system, for example simply at the motor end of drive shaftassembly 22.

Referring now to the enlarged sectional view of the exemplary motormounting structure shown in FIG. 2, secured to the tailcone section 20of the torpedo are a pair of forward and aft ring-shaped ribs 28 and 3%,respectively, which serve to strengthen the tailcone section and alsoform part of the motor mounting structure. The aft end-bell 32 of themotor casing is tapered to provide a generally frusto-conical surface,and the aft rib 30 is pro vided with a like-tapered seat 34. Ring-shapedmember 36, shown as having a substantially L-shaped cross-section andsandwiched between seat 34 of aft rib 30 and the frusto-conical surfaceof end-bell 32, comprises a noiseisolation and shock-absorption materialsuch as a rubber compound preferably having substantially the samestrengths in compression and tension. A noise-isolation member 38 oflike configuration is provided for use at the forward end of motor 12,fitting against the conicallytapered surface of the forward end-bell 40.Continuing with reference additionally to FIGS. 3 and 4, thenoiseisolating motor mounting structure is completed by a generallycylindrical clamp-ring member 42 which makes sliding fit with forwardrib 28, as shown, to seat the an nular comically-tapered flange 44 ofclamp-ring member 42 against the noise-isolation member 38 and toclampingly mount motor 12 in the tailcone section 20. Thecomically-tapered configuration of the several parts of the mountingstructure effect automatic alignment of the motor in the tailconesection. Clamp-ring member 42 is provided with bolt-clearance holes 46,and threaded holes 48 having like spacing are provided in forward rib 28for engagement by clamp-ring bolts 50. For use in the course of motorremoval operations, clamp-ring member 42 may also be provided withjack-screw holes 52 into which, after disengaging the clamp-ring bolts59 from the forward rib 28, the same or other bolts 59' may be threadedto be forced against the forward rib 28 and thus free the clamp ring 42andmotor 12 from binding engagement effected by the conically taperedconfiguration. Reinforcing gussets- 54 may also be provided, as shown,to strengthen the clamp ring member 42 in the regions where it willexperience greatest stress.

As detailed in FIG. which is directed to the aft noiseisolation member36 in particular, the noise-isolation members include inner and outermetal collars 56 and 58, respectively, also generally L-shaped incross-section, the resilient noise-isolation and shock-absorptionmaterial 60 being sandwiched between and bonded to these collars. Theresilient material of the noise-isolation members may further be formedto provide a suitably shaped cavity 62 therein, for example having acorrugated channel configuration as seen in cross-section, to provideexcellent noiseisolation characteristics during torpedo running, but tobecome voidless during shock loading so that it resists damage whichmight otherwise be experienced during transportation or water-entry ofthe torpedo.

Because of the laminated ring configuration, and the distribution oftensile, compressive and shear loads by the resilient material ofL-sh'aped cross-section, a load applied in say a radial direction isopposed by the entire noise-isolation member, rather. than locally, andis absorbed identically for any direction of such radial load. TheL-shaped cross-section also provides the strength necessary to opposeradial distortion of the laminated structure. The transmissioncharacteristics of the resilient material, the laminated structure, thering configuration, and the L-shaped cross-section thus coact to providesignificantly improved strength, noise-isolation and shockprotectioncharacteristics.

Obviously many modifications and variations of the present invention arepossible in the light of the above teachings. It is therefore to beunderstood that the invention may be practiced otherwise than asspecifically disclosed.

What is claimed is:

1. A torpedo motor mounting structure comprising, in combination: atorpedo section; a propulsion motor positioned entirely within saidtorpedo section and having endbells of substantially frusto-conicalconfiguration; said torpedo section having a pair of ring-shaped ribs atthe motor end-bell stations; a clamp-ring member making sliding fit intoone of said ring-shaped ribs and having an annular flange which iscomically tapered to parallel the lateral surface of the endbelladjacent thereto; the other of said ribs having a comically-taperedannular seat facing the lateral surface of the end-bell adjacentthereto; a pair of conically-tapered ring-shaped noise-isolationmembers, one sandwiched between the conically-tapered annular flange ofsaid clamp-ring member and the end-bell adjacent thereto, the othersandwiched between said seat of said other rib and the end-bell adjacentthereto; said clamp-ring member further having a peripheral flangeconfronting the rib adjacent thereto; and bolt means passing throughsaid peripheral flange and threading into the rib adjacent thereto fordrawing said clamp-ring member toward said other rib and therebyclamping said motor in place.

2. A torpedo motor mounting structure in accordance with claim 1,wherein each said ring-shaped noise-isolation member is of laminatedstructure comprising a noiseisolation material sandwiched between andbonded to a pair of inner and outer metal collars, said laminatedstructures each comprising a lateral flange to improve noiseisolationand shock-absorption characteristics.

3. A torpedo motor mounting structure in accordance with claim 2,wherein the noise-isolation materials of said ring-shaped members havecavities formed therein to become closed during shock-loading.

References Cited in the file of this patent UNITED STATES PATENTS

1. A TORPEDO MOTOR MOUNTING STRUCTURE COMPRISING, IN COMBINATION: ATORPEDO SECTION; A PROPULSION MOTOR POSITIONED ENTIRELY WITHIN SAIDTORPEDO SECTION AND HAVING ENDBELLS OF SUBSTANTIALLY FRUSTO-CONICALCONFIGURATION; SAID TORPEDO SECTION HAVING A PAIR OF RING-SHAPED RIBS ATTHE MOTOR END-BELL STATIONS; A CLAMP-RING MEMBER MAKING SLIDING FIT INTOONE OF SAID RING-SHAPED RIBS AND HAVING AN ANNULAR FLANGE WHICH ISCONICALLY TAPERED TO PARALLEL THE LATERAL SURFACE OF THE END-BELLADJACENT THERETO; THE OTHER OF SAID RIBS HAVING A CONICALLY-TAPEREDANNULAR SEAT FACING THE LATERAL SURFACE OF THE END-BELL ADJACENTTHERETO; A PAIR OF CONICALLY-TAPERED RING-SHAPED NOISE-ISOLATIONMEMBERS, ONE SANDWICHED BETWEEN THE CONICALLY-TAPERED ANNULAR